K 10
svn:author
V 3
raj
K 8
svn:date
V 27
2009-08-19T14:48:59.395045Z
K 7
svn:log
V 698
MFC r196380

Fix USB cache sync operations for platforms with non-coherent DMA.

- usb_pc_cpu_invalidate() is called between [consecutive] reads from a device,
  so a sequence of BUS_DMASYNC_POSTREAD and _PREREAD should be used. Note we
  cannot use or'ed shorthand ( _POSTREAD | _PREREAD) for BUS_DMASYNC flags, as
  the low level bus dma sync operation is implementation dependent and we
  cannot assume the required order of operations to be guaranteed.

- usb_pc_cpu_flush() is called before writing to a device, so
  BUS_DMASYNC_PREWRITE should be used.

Submitted by:	Grzegorz Bernacki
Reviewed by:	HPS, arm@, usb@ ML
Tested by:	HPS, Mike Tancsa
Approved by:	re (kib)
Obtained from:	Semihalf

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